This invention is applicable to locks which have only a dead bolt as well as to locks having a dead bolt and a spring latch, or a spring latch only. In all instances a single strike case is needed. Both dead bolt and spring latch are released by the action of a single keeper.
The keeper returns automatically to locked condition when the dead bolt reenters the strike case. The door may be closed with dead bolt extended.
The keeper is held open after the door is opened if the dead bolt was in extended position at the time the door was opened. If only the spring latch is extended but not the dead bolt, the keeper returns to locked condition once the latch has cleared the strike.